Water under the spotlight

Water is one of the greatest challenges of the 21st century. Without it, life cannot flourish. The oceans contain 97.5 %  of all the water on the planet. The remaining 2.5 % is fresh water, although most of this is inaccessible. Some 68.9 % of fresh water is stored in the form of snow or ice (polar ice caps and glaciers), 30.8 % is stored underground as ground water or as soil moisture and what’s left, i.e. 0.3 %, is found in rivers, lakes and reservoirs.



Man has easy access to barely 0.001 % of the total volume water on the planet (200,000 km³). Roughly speaking, just a single drop from each cublic metre of water on Earth is drinking water. Managing this rare resource is becoming vital, because the Earth’s human population is rising, and with it there is an ever greater need for water. There is also the problem of pollution because the available reserves are being increasingly contaminated by human activities.

In partnership with the Artois-Picardi Water Agency, Nausicaa invited a range of experts from the water industry to discuss the questions we are all asking about water quality, water treatment, the situation in this region and pollution..

The debate was moderated by Michel CHEVALET. 

The guest speakers were:

• Alain STREBELLE Director of the Artois Picardie Water Agency
• Didier COCHE Director of Agence Véolia Eau de Boulogne-sur-Mer
• Bruno ROUSSEL, from the National Federation of Farmers’ Trade Unions 
• Jean-Loup LESAFFRE vice-president of CAB (Eau et assainissement)
• Alain LEFEBVRE Ifremer’s Environment and Resources Laboratory

Some brief statistics

• Across the world some 1 million people have no access to drinking water
• Dirty water kills 4,500 children everyday
• 50 cities with more than 6 million inhabitants are running short of water
• In Las Vegas, in the United States, water consumption is running at 1,000 l per person per day
• In Jordan, water is distributed once a week
• In France, we consume 6 billion bottles of water each year

Water treatment

There are several organisations sharing responsibility for water treatment.The Artois Picardie Water Agency is a government body responsible for implementing the government’s water policy, in collaboration with stakeholders. Its mission  is  to improve the quality of the watercourse,  optimise water use, preserve water resources, provide drinking water for all and promote public awareness of the need for effective water management. Water preservation means both maintaining the quality of the water quality and its availability for all.

The director of Véolia Eau reminds us that in France water is free. It’s its treatment which must be paid for. The cost of water is therefore related to the complexity of its treatment. “Water is priceless, but it has a cost”.

Véolia Eau is responsible for transporting water to water purification plants (such as Séliane, in Boulonnais, Pas-de-Calais) and treating it. Once at the plant the water is ”cleaned” before being returned to the environment. Treatment involves several phases: biological treatment using polystyrene beads, UV disinfection and phosphorous and nitrogen removal. The water is also guaranteed odourless. This purification process creates sludge as a by-product, which is dried and incinerated in situ in a special incinerator capable of treating the gases emitted in the process. Alternatively, the sludge can be used by farmers as manure. The new treatment plant Séliane will improve the water quality of the Liane river, as well as the beaches of Boulogne-sur-Mer.

Water consumption: user breakdown

The Water Agency has worked extensively with business and industry. Their water consumption has been reduced by a factor of 3. Agriculture uses about 2 to 3% for crop irrigation. Overall, consumption must not exceed the natural annual rate of renewal. Ground water replenishment is two to three times the extraction rate, so we are not short of water in this region. There was an emergency situation in 2003 with the heat wave of that year, when consumers had to moderate their water consumption, in particular, business and industry..

Sources of pollution

Pollution from heavy metals

The most dangerous form of pollution remains that caused by heavy metals, which produce non-compliant sludge and phosphorous pollution. In respect of industrial pollution, the most worrying aspect remains toxic residual pollution. Penalities in the form of surtax are applied to reduce this form of pollution.

Pollution from nitrates and phosphates

Last March, the European Commission invited France to implement an action plan to reduce the level of nitrate surface water pollution in Brittany. When polluted water reaches the sea (nitrate pollution comes in particular from nitrogenous fertilizers) it causes a phenomenon known as eutrophication, which is an ecosystem imbalance due to  an  excess  of nutrients leading to excessive growth of algae and a reduction in the water’s oxygen content), and is the cause of so-called green tides. In the Nord-Pas de Calais region, the ‘may green’ (or ‘vert de mai’) is the result of the build-up of phytoplanckton mucus. This creates a sort of ”moss”, which can be seen on the region’s beaches from March to June.